Maybe like me you are used to read architecture documents that state that an application should have high availability. It’s not uncommon to read that an application should have four-nine availability (99,99%). But what does it really mean ? In the JBoss in Action book there is a very clear explanation by giving the allowed downtime per year. Here is the table :
Allowed downtime per year
3.1 seconds downtime per year, it’s really not a lot. So if you sign a contract with 99.99999% availability, make sure you have good lawyers around you.
One thought on “High availability. What does it exactly mean ?”
Hi, thanks much for that fun post. I had been hoping to add your Rss but unfortunately it never look like working for me. Do you have other people having one of these problem? Iâ€™ll return to their office in one day perhaps to update. Regardless thanks a whole lot again for the piece.